Transparent polycarbonate polyester composition and process

ABSTRACT

Disclosed is a transparent/translucent molding composition and process for making prepared from an impact modifier and a resin blend of polycarbonate and a cycloaliphatic polyester having a matching index of refraction.

[0001] This application is a continuation-in-part of U.S. patentapplication Ser. No. 09/891,731, filed Jun. 26, 2001; Ser. No.09/690,341, filed Oct. 17, 2000 and Ser. No. 09/690,342, filed Oct. 17,2000, all of which are incorporated herein by reference.

FIELD OF THE INVENTION

[0002] This invention relates to transparent or translucentthermoplastic molding compositions, optionally containing visual-effectcolorants and other additives and processes for producing suchcompositions.

BACKGROUND OF THE INVENTION

[0003] Polycarbonate (PC) is a high-performance plastic with good impactstrength. In addition to ductility (impact strength), general-purpose PChas high transparency, good dimensional stability, low water absorption,good stain resistance and a wide range of colorability. A weak area forPC is its relatively limited range of chemical resistance, whichnecessitates careful appraisal of applications involving contact withcertain organic solvents, some detergents, strong alkali, certain fats,oils and greases. Also, another weak area of PC is that it has a highmelt viscosity which makes it difficult to mold. Medium to high flow PCgrades suffer from the fact that the low temperature ductility issacrificed for a better flow. Finally, PC formulations withvisual-effect additives like metallic type pigments or mineral flakesare in general very brittle at room temperature. This invention dealswith these shortcomings and as such proposes a material that has anunique property profile in terms of transparency, improved chemicalresistance, higher flow and low temperature ductility at −20 to −40° C.,even with special-effect colorants.

[0004] A widely used method to increase low temperature impactresistance, is the addition of impact modifiers to the PC compositions.Adding minor amounts of methylacrylate-butadiene-styrene (MBS) rubbersor Acrylonitrile-butadiene-styrene (ABS) rubbers results in lower D/Btransition temperatures. The major drawback of these modifications isthat, even with only 1% addition levels, the transparency decreases,taking away one of the key properties of PC.

[0005] This opaqueness is caused by the relatively high refractive index(RI) of the aromatic PC (1.58) compared to the more aliphatic rubberyand/or siloxane components, which have RI values in the range 1.48-1.56.

[0006] U.S. Pat. No. 6,040,382 describes how optical clarity of a blendof 2 transparent, immuscible polymers can be improved by addition of athird polymer which is selectively miscible with one of the two originalimmiscible polymers. The concept is based on matching refractiveindexes. This patent is directed to compositions of monovinylaromatic-conjugated diene copolymers (like styrene-butadiene blockcopolymers), styrene-maleic anhydride copolymers (SMA) and poly(alpha-methylstyrene).

[0007] U.S. Pat. No. 5,891,962; U.S. Pat. No. 5,494,969; and U.S. Pat.No. 5,614,589; respectively, describe specific formulations of rubbermodified styrene; cycloolefin polymer composites; andmethacrylate-acrylonitrile-butadiene-styrene copolymers with urethanecopolymer. In these compositions, polymers are being replaced byco-polymers (f.i. polystyrene by a co-polymer of styrene andalkyl(meth)acrylate) to match the RI of a rubbery component. It's alsopossible to modify the rubbery component to match the RI of the polymermatrix, like in U.S. Pat. No. 5,321,056 and U.S. Pat. No. 5,409,967assigned to Rohm and Haas. The focus of all these patents is tochemically modify the ingredients to match RI to achieve transparency.Matching RI to achieve transparency is as such not a novelty.

[0008] U.S. Pat. No. 5,859,119 to Hoefflin relates to reinforced,molding compositions with desirable ductility and melt flow properties.The composition contains a cyclo aliphatic polyester resin, an impactmodifying amorphous resin which increases the ductility of the polyesterresin but reduces the melt flow properties thereof, and a high molecularweight polyetherester polymer which increases the melt flow propertiesof the polyester polymer without reducing the ductility thereof, and aglass filler to reinforce and stiffen the composition and form areinforced molding composition. This invention is focussed on opaque PCblends, rather than transparent blends.

[0009] U.S. Pat. No. 4,188,314 describes shaped articles (such as sheetand helmets) of blends of 25-98 parts by weight (pbw) of an aromaticpolycarbonate and 2-75 pbw of a poly cyclohexane dimethanol phthalatewhere the phthalate is from 5-95% isophthalate and 95-10% terephthalate.Articles with enhanced solvent resistance and comparable opticalproperties and impact to the base polycarbonate resin and superioroptical properties to an article shaped from a polycarbonate and anaromatic polyester, such as polyalkylene terephthalate, are disclosed.

[0010] There are other patents that deal with polycarbonatepolycyclohexane dimethanol phthalate blends for example; U.S. Pat. No.4,125,572; U.S. Pat. No. 4,391,954; 4,786,692; 4,897,453 and 5,478,896.U.S. Pat. No. 5,478,896 relates to transparent polycarbonate blends with10-99% polyester of CHDM with some minor amount of aliphatic diol andiso and terephthalic acid. U.S. Pat. No. 4,786,692 relates to a 2-98%aromatic polycarbonate blend with a polyester made of cyclohexanedimethanol (CHDM) and ethylene glycol (EG) in a 1:1 to 4:1 ratio withiso and terephthalic acid. U.S. Pat. No. 4,391,954 describes compatiblecompositions of non halogen polycarbonate (PC) and amorphous polyestersof CHDM and a specific iso/tere phthalate mixture. U.S. Pat. No.4,125,572 relates to a blend of 40-95% PC, 5-60% polybutyleneterephthalate (PBT) 1-60% and 1-60% an aliphatic/cycloaliphaticiso/terephthalate resin. U.S. Pat. No. 4,897,453 describes blends of10-90 % PC, 10-90% of a polyester of 0.8-1.5 IV, comprised of1,4-cyclohexane dicarboxylic acid, 70% trans isomer, CHDM and 15-50 wt.% poly oxytetramethylene glycol with 0-1.5 mole % branching agent. Alsoclaimed are molded or extruded articles of the composition.

SUMMARY OF THE INVENTION

[0011] The present invention provides compositions with improvedductility and melt flow propeties, and good baseline transparency, whichcan then be reduced if and as desired for a specific application by theaddition of visual-effects additives. The composition comprises auniform blend of:

[0012] (a) a miscible resin blend of a polycarbonate resin and acycloaliphatic polyester resin, said cycloaliphatic polyester resincomprising the reaction product of an aliphatic C₂-C₁₂ diol or chemicalequivalent and a C₆-C₁₂ aliphatic diacid or chemical equivalent, saidcycloaliphatic polyester resin containing at least about 80% by weightof a cycloaliphatic dicarboxylic acid, or chemical equivalent, and/or ofa cycloaliphatic diol or chemical equivalent;

[0013] (b) an impact modifying amorphous resin having a refractive indexfrom about 1.51 to about 1.58 for increasing the low temperatureductility of the resin molding composition;

[0014] wherein the proportions in the blend of polycarbonate and thecycloaliphatic polyester resin are selected so that the index ofrefraction substantially matches the index of refraction of said impactmodifier.

[0015] In one embodiment, transparent and low temperature ductilepolycarbonate (PC) blends are obtained via the addition ofpoly(cyclohexane dimethanol cyclohexane dicarboxylate) (PCCD) and animpact modifier. The complete miscibility of PC and PCCD permits thematching of refractive index (RI) of the impact modifier with the RI ofthe PC/PCCD blend, by adjusting the PC/PCCD ratio. Examples of suchimpact modifiers are MBS/ABS type of rubbers with a particle size rangefrom 50-1000 nm, the rubber being butadiene or styrene-butadiene withstyrene content of up to 40%. Styrene to acrylonitrile ratio in ABSrubbers can be between 100/0 and 50/50 with a preferred ratio of 80/20to 70/30. Typical examples are ABS 415 (RI=1.542) and ABS 336(RI=1.546), both produced by GE Plastics and BTA702, BTA736, being MBSmaterials and produced by Rohm & Haas. All these rubbers are used in thePVC market as impact modifiers to improve the toughness of PVC withoutloosing the transparency.

[0016] The application further provides a method for the production ofcompositions with improved ductility and melt flow propeties, and goodbaseline transparency, which can then be reduced if and as desired for aspecific application by the addition of visual-effects additives. Inaccordance with one embodiment of the method of the invention, amiscible resin blend of a polycarbonate resin and a cycloaliphaticpolyester resin is prepared. The proportions of the polycarbonate resinand the cycloaliphatic polyester resin are selected such that the blendhas a refractive index that is intermediate between the refractiveindices of the two components, and that substantially matches therefractive index of an impact modifier which is added to form the finalcomposition.

DETAILED DESCRIPTION OF THE INVENTION

[0017] The composition of the present invention comprise miscible resinblend of a polycarbonate resin and a cycloaliphatic polyester resin,said cycloaliphatic polyester resin comprising the reaction product ofan aliphatic C₂-C₁₂ diol or chemical equivalent and a C₆-C₁₂ aliphaticdiacid or chemical equivalent, said cycloaliphatic polyester resincontaining at least about 80% by weight of a cycloaliphatic dicarboxylicacid, or chemical equivalent, and/or of a cycloaliphatic diol orchemical equivalent.

Polycarbonate Resin

[0018] Polycarbonates useful in the invention comprise the divalentresidue of dihydric phenols, Ar′, bonded through a carbonate linkage andare preferably represented by the general formula III:

[0019] wherein A is a divalent hydrocarbon radical containing from 1 toabout 15 carbon atoms or a substituted divalent hydrocarbon radicalcontaining from 1 to about 15 carbon atoms; each X is independentlyselected from the group consisting of hydrogen, halogen, and amonovalent hydrocarbon radical such as an alkyl group of from 1 to about8 carbon atoms, an aryl group of from 6 to about 18 carbon atoms, anarylalkyl group of from 7 to about 14 carbon atoms, an alkoxy group offrom 1 to about 8 carbon atoms; and m is 0 or 1 and n is an integer offrom 0 to about 5. Ar′ may be a single aromatic ring like hydroquinoneor resorcinol, or a multiple aromatic ring like biphenol or bisphenol A.

[0020] The dihydric phenols employed are known, and the reactive groupsare thought to be the phenolic hydroxyl groups. Typical of some of thedihydric phenols employed are bis-phenols such asbis(4-hydroxyphenyl)methane, 2,2-bis(4-hydroxyphenyl)propane (also knownas bisphenol-A), 2,2-bis(4-hydroxy-3,5-dibromo-phenyl)propane; dihydricphenol ethers such as bis(4-hydroxyphenyl)ether,bis(3,5-dichloro-4-hydroxyphenyl)ether; p,p′-dihydroxydiphenyl and3,3′-dichloro-4,4′-dihydroxydiphenyl; dihydroxyaryl sulfones such asbis(4-hydroxyphenyl)sulfone, bis(3,5-dimethyl-4-hydroxyphenyl)sulfone,dihydroxy benzenes such as resorcinol, hydroquinone, halo- andalkyl-substituted dihydroxybenzenes such as1,4-dihydroxy-2,5-dichlorobenzene, 1,4-dihydroxy-3-methylbenzene; anddihydroxydiphenyl sulfides and sulfoxides such asbis(4-hydroxyphenyl)sulfide, bis(4-hydroxy-phenyl)sulfoxide andbis(3,5-dibromo-4-hydroxyphenyl)sulfoxide. A variety of additionaldihydric phenols are available and are disclosed in U.S. Pat. Nos.2,999,835, 3,028,365 and 3,153,008; all of which are incorporated hereinby reference. It is, of course, possible to employ two or more differentdihydric phenols or a combination of a dihydric phenol with a glycol.

[0021] The carbonate precursors are typically a carbonyl halide, adiarylcarbonate, or a bishaloformate. The carbonyl halides include, forexample, carbonyl bromide, carbonyl chloride, and mixtures thereof. Thebishaloformates include the bishaloformates of dihydric phenols such asbischloroformates of 2,2-bis(4-hydroxyphenyl)-propane, hydroquinone, andthe like, or bishaloformates of glycol, and the like. While all of theabove carbonate precursors are useful, carbonyl chloride, also known asphosgene, and diphenyl carbonate are preferred.

[0022] The aromatic polycarbonates can be manufactured by any processessuch as by reacting a dihydric phenol with a carbonate precursor, suchas phosgene, a haloformate or carbonate ester in melt or solution. U.S.Pat. No. 4,123,436 describes reaction with phosgene and U.S. Pat. No.3,153,008 describes a transesterification process.

[0023] Preferred polycarbonate will be made of dihydric phenols thatresult in resins having low birefringence for example dihydric phenolshaving pendant aryl or cup shaped aryl groups like:

[0024] Phenyl-di(4-hydroxyphenyl)ethane (acetophenone bisphenol):

[0025] Diphenyl-di(4-hydroxyphenyl)methane (benzophenone bisphenol):

[0026] 2,2-bis(3-phenyl-4-hydroxyphenyl)propane

[0027] 2,2-bis-(3,5-diphenyl-4-hydroxyphenyl)propane;

[0028] bis-(2-phenyl-3-methyl-4-hydroxyphenyl)propane;

[0029] 2,2′-bis(hydroxyphenyl)fluorene;

[0030] 1,1-bis(5-phenyl-4-hydroxyphenyl)cyclohexane;

[0031] 3,3′-diphenyl-4,4′-dihydroxy diphenyl ether;

[0032] 2,2-bis(4-hydroxyphenyl)-4,4-diphenyl butane;

[0033] 1,1-bis(4-hydroxyphenyl)-2-phenyl ethane;

[0034] 2,2-bis(3-methyl-4-hydroxyphenyl)-1-phenyl propane;

[0035] 6,6′-dihdyroxy-3,3,3′,3′-tetramethyl-1,2′-spiro(bis)indane;

[0036] (hereinafter “SBI”), or dihydric phenols derived from spirobiindane of formula IV:

[0037] Units derived from SBI and its 5-methyl homologue are preferred,with SBI being most preferred.

[0038] Other dihydric phenols which are typically used in thepreparation of the polycarbonates are disclosed in U.S. Pat. Nos.2,999,835, 3,038,365, 3,334,154 and 4,131,575. Branched polycarbonatesare also useful, such as those described in U.S. Pat. Nos. 3,635,895 and4,001,184. Polycarbonate blends include blends of linear polycarbonateand branched polycarbonate.

[0039] It is also possible to employ two or more different dihydricphenols or a copolymer of a dihydric phenol with an aliphaticdicarboxylic acids like; dimer acids, dodecane dicarboxylic acid, adipicacid, azelaic acid in the event a carbonate copolymer or interpolymerrather than a homopolymer is desired for use in the preparation of thepolycarbonate mixtures of the invention. Most preferred are aliphatic C5to C12 diacid copolymers.

[0040] The preferred polycarbonates are preferably high molecular weightaromatic carbonate polymers have an intrinsic viscosity (as measured inmethylene chloride at 25° C.) ranging from about 0.30 to about 1.00dl/gm. Polycarbonates may be branched or unbranched and generally willhave a weight average molecular weight of from about 10,000 to about200,000, preferably from about 20,000 to about 100,000 as measured bygel permeation chromatography. It is contemplated that the polycarbonatemay have various known end groups.

Cycloaliphatic Polyester Resin

[0041] The cycloaliphatic polyester resin comprises a polyester havingrepeating units of the formula I:

[0042] where at least one R or R1 is a cycloalkyl containing radical.

[0043] The polyester is a condensation product where R is the residue ofan aryl, alkane or cycloalkane containing diol having 6 to 20 carbonatoms or chemical equivalent thereof, and R1 is the decarboxylatedresidue derived from an aryl, aliphatic or cycloalkane containing diacidof 6 to 20 carbon atoms or chemical equivalent thereof with the provisothat at least one R or R1 is cycloaliphatic. Preferred polyesters of theinvention will have both R and R1 cycloaliphatic.

[0044] The present cycloaliphatic polyesters are condensation productsof aliphatic diacids, or chemical equivalents and aliphatic diols, orchemical equivalents. The present cycloaliphatic polyesters may beformed from mixtures of aliphatic diacids and aliphatic diols but mustcontain at least 50 mole % of cyclic diacid and/or cyclic diolcomponents, the remainder, if any, being linear aliphatic diacids and/ordiols. The cyclic components assist by imparting good rigidity to thepolyester and to allow the formation of transparent blends due tofavorable interaction with the polycarbonate resin.

[0045] The polyester resins are typically obtained through thecondensation or ester interchange polymerization of the diol or diolequivalent component with the diacid or diacid chemical equivalentcomponent. Two types of cycloaliphatic polyesters can be used withBPA-based polycarbonate to give the compositions and articles of thisinvention. The most preferred polyester molecules are derived fromcycloaliphatic diol and cycloaliphatic diacid compounds, for examplepolycyclohexane dimethanol cyclohexyl dicarboxylate (PCCD). Polyestershaving only one cyclic unit may also be useful. An extra advantage ofadding these aliphatic polyesters to PC is that their low glasstransition temperature (Tg) improves the flow of PC (or impact modifiedPC) significantly, resulting in an overall very favorable flow/impactbalance. Another advantage is that the polyester improves the overallchemical resistance towards various chemicals that are very aggressivetowards straight PC. Examples of these chemicals are acetone,coppertone, gasoline, toluene etc.

[0046] R and R1 are preferably cycloalkyl radicals independentlyselected from the following formula:

[0047] The preferred cycloaliphatic radical R1 is derived from the1,4-cyclohexyl diacids and most preferably greater than 70 mole %thereof in the form of the trans isomer. The preferred cycloaliphaticradical R is derived from the 1,4-cyclohexyl primary diols such as1,4-cyclohexyl dimethanol, most preferably more than 70 mole % thereofin the form of the trans isomer.

[0048] Other diols useful in the preparation of the polyester resins ofthe present invention are straight chain, branched, or cycloaliphaticalkane diols and may contain from 2 to 12 carbon atoms. Examples of suchdiols include but are not limited to ethylene glycol; propylene glycol,i.e., 1,2- and 1,3-propylene glycol; 2,2-dimethyl-1,3-propane diol;2-ethyl, 2-methyl, 1,3-propane diol; 1,3- and 1,5-pentane diol;dipropylene glycol; 2-methyl-1,5-pentane diol; 1,6-hexane diol;dimethanol decalin, dimethanol bicyclo octane; 1,4-cyclohexanedimethanol and particularly its cis- and trans-isomers;2,2,4,4-tetramethyl-1,3-cyclobutanediol (TMCBD), triethylene glycol;1,10-decane diol; and mixtures of any of the foregoing. Preferably acycloaliphatic diol or chemical equivalent thereof and particularly1,4-cyclohexane dimethanol or its chemical equivalents are used as thediol component.

[0049] Chemical equivalents to the diols include esters, such asdialkylesters, diaryl esters and the like.

[0050] The diacids useful in the preparation of the aliphatic polyesterresins of the present invention preferably are cycloaliphatic diacids.This is meant to include carboxylic acids having two carboxyl groupseach of which is attached to a saturated carbon. Preferred diacids arecyclo or bicyclo aliphatic acids, for example, decahydro naphthalenedicarboxylic acids, norbornene dicarboxylic acids, bicyclo octanedicarboxylic acids, 1,4-cyclohexanedicarboxylic acid or chemicalequivalents, and most preferred is trans-1,4-cyclohexanedicarboxylicacid or chemical equivalent. Linear dicarboxylic acids like adipic acid,azelaic acid, dicarboxyl dodecanoic acid and succinic acid may also beuseful.

[0051] Cyclohexane dicarboxylic acids and their chemical equivalents canbe prepared, for example, by the hydrogenation of cycloaromatic diacidsand corresponding derivatives such as isophthalic acid, terephthalicacid or naphthalenic acid in a suitable solvent such as water or aceticacid using a suitable catalysts such as rhodium supported on a carriersuch as carbon or alumina. See, Friefelder et al., Journal of OrganicChemistry, 31, 3438 (1966); U.S. Pat. Nos. 2,675,390 and 4,754,064. Theymay also be prepared by the use of an inert liquid medium in which aphthalic acid is at least partially soluble under reaction conditionsand with a catalyst of palladium or ruthenium on carbon or silica. See,U.S. Pat. Nos. 2,888,484 and 3,444,237.

[0052] Typically, in the hydrogenation, two isomers are obtained inwhich the carboxylic acid groups are in cis- or trans-positions. Thecis- and trans-isomers can be separated by crystallization with orwithout a solvent, for example, n-heptane, or by distillation. Thecis-isomer tends to blend better; however, the trans-isomer has highermelting and crystallization temperatures and may be preferred. Mixturesof the cis- and trans-isomers are useful herein as well.

[0053] When the mixture of isomers or more than one diacid or diol isused, a copolyester or a mixture of two polyesters may be used as thepresent cycloaliphatic polyester resin.

[0054] Chemical equivalents of these diacids include esters, alkylesters, e.g., dialkyl esters, diaryl esters, anhydrides, salts, acidchlorides, acid bromides, and the like. The preferred chemicalequivalents comprise the dialkyl esters of the cycloaliphatic diacids,and the most favored chemical equivalent comprises the dimethyl ester ofthe acid, particularly dimethyl-1,4-cyclohexane-dicarboxylate.

[0055] A preferred cycloaliphatic polyester ispoly(cyclohexane-1,4-dimethylene cyclohexane-1,4-dicarboxylate) alsoreferred to as poly(1,4-cyclohexane-dimethanol-1,4-dicarboxylate) (PCCD)which has recurring units of formula II:

[0056] With reference to the previously set forth general formula, forPCCD, R is derived from 1,4 cyclohexane dimethanol; and R1 is acyclohexane ring derived from cyclohexanedicarboxylate or a chemicalequivalent thereof. The favored PCCD has a cis/trans formula.

[0057] The polyester polymerization reaction is generally run in themelt in the presence of a suitable catalyst such as a tetrakis (2-ethylhexyl) titanate, in a suitable amount, typically about 50 to 200 ppm oftitanium based upon the final product.

[0058] The preferred aliphatic polyesters used in the presenttransparent molding compositions have a glass transition temperature(Tg) which is above 50° C., more preferably above 80° C. and mostpreferably above about 100° C.

[0059] Also contemplated herein are the above polyesters with from about1 to about 50 percent by weight, of units derived from polymericaliphatic acids and/or polymeric aliphatic polyols to form copolyesters.The aliphatic polyols include glycols, such as poly(ethylene glycol) orpoly(butylene glycol). Such polyesters can be made following theteachings of, for example, U.S. Pat. Nos. 2,465,319 and 3,047,539.

Miscible Resin Blend

[0060] In the miscible resin blend of the invention, the preferredpolycarbonate will be composed of units of BPA, SBI bisphenol, arylsubstituted bisphenols, cycloaliphatic bisphenols and mixtures thereof.The most preferred materials will be blends where the polyester has bothcycloaliphatic diacid and cycloaliphatic diol components specificallypolycyclohexane dimethanol cyclohexyl dicarboxylate (PCCD).

[0061] In the miscible resin blends, a ratio of cycloaliphatic polyesterto polycarbonate in the range of 80:20 to 5:95% by weight of the entiremixture is preferred. Blends from 70:30 to 40:60 are most preferred.

[0062] The refractive index of the miscible resin blend is determined bythe components and the amounts of each. The refractive index of purepolycarbonate (PC) is 1.586 while that of PCCD is 1.516. In a mixture ofpolycarbonate and poly(1,4-cyclohexanedimethanol-1,4-cyclohexanedicarboxylate the refractiveindex of the mixture, y, varies as the function −0.0007 (weight percentpoly (1,4-cyclohexanedimethanol-1,4-cyclohexanedicarboxylate)+1.586 witha regression R squared coefficient of 0.998. Similarly, resorcinoldiphosphate (RDP) has a refractive index of 1.5673. A mixture having 25weight percent RDP in PC would result in a calculate refractive index of0.25(1.5673)+0.75(1.586)=1.581. Thus the refractive index of the mixtureof the two components may be controlled between the upper and lowerlimits of their respective indices of refraction.

Impact Modifier

[0063] The compositions of the invention further comprise asubstantially amorphous impact modifier copolymer resin that is added tothe miscible resin blend in an amount between about 1 and 30% by weight.The impact modifier may comprise one of several different rubberymodifiers such as graft or core shell rubbers or combinations of two ormore of these modifiers. Suitable are the groups of modifiers known asacrylic rubbers, ASA rubbers, diene rubbers, organosiloxane rubbers,EPDM rubbers, SBS or SEBS rubbers, ABS rubbers, MBS rubbers and glycidylester impact modifiers.

[0064] The term acrylic rubber modifier can refer to multi-stage,core-shell, interpolymer modifiers having a cross-linked or partiallycrosslinked (meth)acrylate rubbery core phase, preferably butylacrylate. Associated with this cross-linked acrylic ester core is anouter shell of an acrylic or styrenic resin, preferably methylmethacrylate or styrene, which interpenetrates the rubbery core phase.Incorporation of small amounts of other monomers such as acrylonitrileor (meth)acrylonitrile within the resin shell also provides suitableimpact modifiers. The interpenetrating network is provided when themonomers forming the resin phase are polymerized and cross-linked in thepresence of the previously polymerized and cross-linked (meth)acrylaterubbery phase.

[0065] Preferred rubbers are graft or core shell structures with arubbery component with a Tg below 0° C., preferably between about −40°to −80° C., composed of poly alkylacrylates or polyolefins grafted withPMMA or SAN. Preferably the rubber content is at least 40 wt %, mostpreferably between about 60-90wt %.

[0066] Especially suitable rubbers are the butadiene core-shell polymersof the type available from Rohm & Haas, for example Paraloid® EXL2600.Most preferably, the impact modifier will comprise a two stage polymerhaving an butadiene based rubbery core and a second stage polymerizedfrom methylmethacrylate alone or in combination with styrene.Surprisingly, with opaque impact modifiers like MBS EXL2600, the effectof adding PCCD to these PC/impact modifier compositions had very similarresults; high transmissions and low haze values were obtained withmodifiers, each modifier having a unique PC/PCCD ratio to match the R1of thermoplastic blend to the R1 of the impact modifier.

[0067] Other suitable rubbers are the ABS types Blendex® 336 and 415,available form GE Specialty Chemicals. Both rubbers are based on impactmodifier resin of SBR rubber. Although the mentioned rubbers appear tobe very suitable, there are many more rubbers which can be used.Actually any rubber which has a reasonable clarity and which has an R1between the R1 of the components of the miscible resin blend can beused, for example between 1.51 and 1.58 when the blend is PC and PCCDcan be used to the present invention.

[0068] The ABS type thermoplastic resins utilized by the presentinvention are graft copolymers of vinyl cyanide monomers, di-olefins,vinyl aromatic monomers and vinyl carboxylic acid ester monomers. Thusapplicants define herein the phrase ABS type oracrylonitrile-butadiene-styrene type to include the group of polymersderived from vinyl cyanide monomers, di-olefins, vinyl aromatic monomersand vinyl carboxylic acid ester monomers as hereinafter defined. Vinylcyanide monomers are herein defined by the following structural formula:

[0069] where R is selected from the group consisting of hydrogen, alkylgroups of from 1 to 5 carbon atoms, bromine and chlorine. Examples ofvinyl cyanide monomers include acrylonitrile, methacrylonitrile,ethacrylonitrile, (-chloroacrylonitrile and (-bromoacrylonitrile. Thediolefins utilized in the present invention are herein defined by thefollowing structural formula:

[0070] where each Q is independently selected from the group consistingof hydrogen, alkyl groups of from 1 to 5 carbon atoms, bromine andchlorine. Examples of di-olefins include butadiene, isoprene,1,3-heptadiene, methyl-1,3-pentadiene, 2,3-dimethylbutadiene,2-ethyl-1,3-pentadiene, 1,3-hexadiene, 2,4-hexadiene, chlorobutadiene,bromobutadiene, dichlorobutadiene, dibromobutadiene and mixturesthereof. Vinyl aromatic monomers are herein defined by the followingstructural formula:

[0071] where each X is independently selected from the group consistingof hydrogen, alkyl groups of from 1 to 5 carbon atoms, cycloalkyl, aryl,alkaryl, aralkyl, alkoxy, aryloxy and halogen and where R isindependently selected from the group consisting of hydrogen, alkylgroups of from 1 to 5 carbon atoms, bromine and chlorine. The phraseindependently selected means that co-polymers, terpolymers, or otherinterpolymers of these vinyl cyanide monomers may have an independentlyselected R for the vinyl cyanide relative to the R selected for thevinyl aromatic monomer. Examples of substituted vinyl aromatic monomersinclude styrene, 4-methylstyrene, vinyl xylene, 3,5-diethylstyrene,p-tert-butyl-styrene, 4-n-propyl styrene, (-methyl-styrene,(-ethyl-styrene, (-methyl-p-methylstyrene, p-hydroxy-styrene,methoxy-styrenes, chloro-styrene, 2-methyl-4-chloro-styrene,bromo-styrene, (-chloro-styrene, (-bromo-styrene, dichloro-styrene,2,6-dichloro-4-methylstyrene, dibromo-styrene, tetrachloro-styrene andmixtures thereof. Vinyl carboxylic acid ester monomers (esters ofalpha-, beta-u unsaturated carboxylic acids) are herein defined by thefollowing structural formula:

[0072] where J is selected from the group consisting of hydrogen andalkyl groups of from 1 to 8 carbon atoms and A is selected from thegroup consisting of alkyl groups of from 1 to 5 carbon atoms. Examplesof vinyl carboxylic acid ester monomers include methyl methacrylate,methyl acrylate, ethyl methacrylate, ethyl acrylate, butyl methacrylate,butyl acrylate, propyl methacrylate, propyl acrylate, 2-ethylhexylacrylate, 2-ethylhexyl methacrylate, methyl ethacrylate and mixturesthereof.

[0073] It will be understood that by the use of “monomers” are includedall of the polymerizable species of monomers and copolymers typicallyutilized in polymerization reactions, including by way of examplemonomers, homopolymers of primarily a single monomer, copolymers of twoor more monomers, terpolymers of three monomers and physical mixturesthereof. For example, a mixture of polymethylmethacrylate (PMMA)homopolymer and styrene-acrylonitrile (SAN) copolymer may be utilized toform the “free rigid phase”, or alternatively amethylmethacrylate-styrene-acrylonitrile (MMASAN) terpolymer may beutilized.

[0074] Various monomers may be further utilized in addition to or inplace of those listed above to further modify various properties of thecompositions disclosed herein. In general, the components of the presentinvention may be compounded with a copolymerizable monomer or monomerswithin a range not damaging the objectives and advantages of thisinvention. For example, in addition to or in place of SBR, the rubberphase may be comprised of polybutadiene, butadiene-acrylonitrilecopolymers, polyisoprene, EPM and EPR rubbers (ethylene/propylenerubbers), EPDM rubbers (ethylene/propylene/non-conjugated diene rubbers)and crosslinked alkylacrylate rubbers based on C₁-C₈ alkylacrylates, inparticular ethyl, butyl and ethylhexylacrylates, either alone or as amixture of two or more kinds. Furthermore, the rubber may compriseeither a block or random copolymer. In addition to or in place ofstyrene and acrylonitrile monomer used in the graft or free rigid phase,monomers including vinyl carboxylic acids such as acrylic acid,methacrylic acid and itaconic acid, acrylamides such as acrylamide,methacrylamide and n-butyl acrylamide, alpha-, beta-unsaturateddicarboxylic anhydrides such as maleic anhydride and itaconic anhydride,imides of alpha-, beta-unsaturated dicarboxylic acids such as maleimide,N-methylmaleinide, N-ethylmaleimide, N-Aryl maleimide and the halosubstituted N-alkyl N-aryl maleimides, imidized polymethyl methacrylates(polyglutarimides), unsaturated ketones such as vinyl methyl ketone andmethyl isopropenyl ketone, alpha-olefins such as ethylene and propylene,vinyl esters such as vinyl acetate and vinyl stearate, vinyl andvinylidene halides such as the vinyl and vinylidene chlorides andbromides, vinyl-substituted condensed aromatic ring structures such asvinyl naphthalene and vinyl anthracene and pyridine monomers may beused, either alone or as a mixture of two or more kinds.

[0075] Preferred impact modifiers are of the type disclosed in U.S. Pat.No. 4,292,233, incorporated by reference. These impact modifierscomprise, generally, a relatively high content of a cross-linkedbutadiene polymer grafted base having grafted thereon acrylonitrile andstyrene.

[0076] The acrylonitrile-butadiene-styrene type (ABS) thermoplasticresin is preferably based on a SBR high rubber graft with a SAN freerigid phase. Rubber amounts between about 20 percent and about 45percent are preferred. This ABS composition preferably comprises: a) afree rigid phase derived from a vinyl aromatic monomer and a vinylcarboxylic acid ester monomer, wherein the free rigid phase is presentat a weight percent level of from about 30 to about 70 percent by weightbased on the total weight of the composition, more preferably from about35 to about 50 percent by weight thereof, and most preferably from about38 to about 47 percent by weight thereof; b) a graft copolymer (graftphase) comprising a substrate copolymer and a superstrate copolymerwherein the substrate copolymer comprises a copolymer derived from avinyl aromatic monomer and a di-olefin and wherein the superstratecopolymer comprises a copolymer derived from an aromatic monomer whereinthe graft copolymer is present at a level of from about 30 to about 70weight percent of the total weight of the composition, more preferablyfrom about 50 to about 65 percent by weight thereof, and most preferablyfrom about 53 to about 62 percent by weight thereof; and c) wherein therefractive index of the free rigid phase and the calculated refractiveindex of the graft phase are approximately the same (that is, matched towithin about 0.005 or less). The refractive index of the phases may bereadily calculated based on the weight percentage of the components andtheir refractive indices, for example:

[0077] The refractive indices of butadiene, styrene, acrylonitrile andmethyl methacrylate homo-polymers are 1.515, 1.591, 1.515 and 1.491respectively. A butadiene/styrene ratio of 85:15 gives a calculatedrefractive index of (0.85×1.515)+(0.15×1.591)=˜1.526.

[0078] The grafted SAN having a styrene to acrylonitrile ratio of 80:20gives a calculated refractive index of (0.80×1.591)+(0.20×1.515)=˜1.576.

[0079] A graft copolymer of 65% styrene-butadiene rubber (butadiene:styrene=85:15) and 35% grafted SAN (styrene: acrylonitrile=80:20) givesa calculated refractive index of (0.65×1.526)+(0.35×1.576)=˜1.544.

[0080] In the example above, the free rigid phase must haveapproximately the same refractive index as the graft rubber phase within±0.005. A free rigid phase of 60% PMMA and 40 percent SAN of 75% styreneand 25% acrylonitrile has a refractive index of approximately 1.539,thereby matching the graft phase refractive index to within 0.005.

[0081] The free rigid phase is preferably derived fromstyrene-acrylonitrile (SAN). The ratio of styrene to acrylonitrile ispreferably from 1.5 to 15 (that is, preferably from about 60 percent toabout 94 percent styrene) and from about 6 percent to about 40 percentacrylonitrile by weight based on the total weight of the free rigidphase, more preferably from about 4 to 12 (from about 80 percent toabout 92 percent styrene) and from about 8 percent to about 20 percentacrylonitrile by weight based on the total weight of the free rigidphase and most preferably from about 6 to 9 (from about 85 percent toabout 90 percent styrene) and from about 10 percent to about 15 percentacrylonitrile by weight based on the total weight of the free rigidphase. The graft copolymer is preferably derived from a vinylaromatic-di-olefin rubber substrate copolymer. The graft copolymerpreferably comprises from about 40 percent to about 90 percent of asubstrate copolymer and from about 10 percent to about 60 percent of asuperstrate copolymer based on the total weight of the graft copolymer,more preferably from about 55 percent to about 75 percent of a substratecopolymer and from about 25 percent to 45 percent of a superstratecopolymer by weight thereof, and most preferably about 65 percent byweight of a substrate copolymer and 35 percent by weight of asuperstrate copolymer. The substrate copolymer preferably comprises avinyl aromatic component level of from slightly greater than about 0percent to about 30 percent by weight based on the total weight of thesubstrate copolymer, more preferably from 10 to 20 percent by weightthereof and most preferably 15 percent by weight thereof, and adi-olefin component level of from about 70 percent to about 100 percentof a di-olefin by weight based on the total weight of the substratecopolymer, more preferably from about 80 to about 90 percent by weightthereof, and most preferably about 85 percent by weight thereof. Thesuperstrate may optionally contain a vinyl carboxylic acid estercomponent such as methyl methacrylate. The graft phase preferably has aweight average particle size of less than 2400 angstroms (0.24 microns),more preferably less than 1600 angstroms (0.16 microns) and mostpreferably less than 1200 angstroms (0.12 microns). Generally, theparticle size of the rubber has an effect upon the optimum graftinglevel for the graft copolymer. As a given weight percentage of smallersize rubber particles will provide greater surface area for graftingthan the equivalent weight of a larger rubber particle size, the densityof grafting may be varied accordingly. In general, smaller rubberparticles preferably utilize a higher superstrate/substrate ratio thanlarger size particles to give generally comparable results.

[0082] The graft phase may be coagulated, blended and colloided with thefree rigid phase homopolymers, copolymers and/or terpolymers by thevarious blending processes that are well known in the art to form theASA polymer polyblend.

Preferred Compositions of the Invention

[0083] The preferred impact-modified, cycloaliphatic polymercompositions of the, present invention comprise:

[0084] (A) from 20 to 80% by weight of a blend of polycarbonate andcyclo aliphatic polyester resin, where the ratio of polycarbonate tocyclo aliphatic polyester resin is from 20/80 to 95/5, preferable from30/70 to 60/40, the cyclo aliphatic polyester comprises the reactionproduct of:

[0085] (a) at least one straight chain, branched, or cycloaliphaticC₂-C₁₂ alkane diol, most preferably a C₆-C₁₂ cycloaliphatic diol, orchemical equivalent thereof; and

[0086] (b) at least one cycloaliphatic diacid, most preferably a C₆-C₁₂diacid, or chemical equivalent thereof; and

[0087] (B) from 1 to 30%, preferably from 5 to 20% by weight of animpact modifier comprising a substantially amorphous resin comprisingone of several different modifiers or combinations of two or more ofthese modifiers. Suitable are the groups of modifiers known as ABSmodifiers ASA modifiers, MBS modifiers, EPDM graft SAN modifiers,acrylic rubber modifiers.

[0088] The method of blending the compositions can be carried out byconventional techniques. Preferably the polyester and polycarbonate arepre-blended in an amount selected to match the refractive index of themodifier. The ingredients are typically in powder or granular form,extruding the blend and comminuting into pellets or other suitableshapes. The ingredients are combined in any usual manner, e.g., by drymixing or by mixing in the melted state in an extruder, or in othermixers.

[0089] Impact modified polycarbonate resins as outlined above areexcellent materials for applications requiring high impact, chemicalresistance, and appealing aesthetic. In order to improve the appearance,special effect additives have been utilized as colorants. U.S. Pat. No.5,510,398 to Clark et al relates to a highly filled, extrudedpolyalkylene terephthalate resin, a polycarbonate resin, a filler, astabilizer, and a non-dispersing pigment to give the extrudedthermoplastic material a speckled surface appearance. Column 5, lines 35to column 6, line 61, describes impact modifiers. U.S. Pat. No.5,441,997 to Walsh et al describes the use of impact modifiers inconjunction with polycarbonate/polyester compositions having a bariumsulfate, strontium sulfate, zirconium oxide, or zinc sulfate filler.U.S. Pat. No. 5,814,712 to Gallucci et al describes a glycidyl ester asan impact modifier, and optionally other impact modifiers, for apolycarbonate/polyester resin. U.S. Pat. No. 4,264,487 to Fromuth et aldescribes aromatic polycarbonate, acrylate-based core-shell polymer, andaromatic polyester.

Visual-Effect Additives

[0090] In the compositions of the invention, one or more visual-effectsadditives of various types may be added as desired.

Glitter Type of Materials

[0091] As the glitter material, it is suitable to use one or more kindsselected from the group consisting of mica, pearl mica, glass flake,aluminum powder, stainless powder, brass powder, metallic platingpowder, metallic coating powder, aluminum flake, aluminum foil, zinc,and bronze powder. This leads to an advantage of an excellent glitterfeeling. It is particularly preferable to use a glitter material havinga high transmittance with respect to a visible ray such as mica, pearlmica, glass flake, or the like. These materials further improve theglitter and color depth of a skin layer, and moreover, provide a colortone with high gloss, depth and glitter feel to the glitter resin moldedmaterial by light that has transmitted through the skin layer andreflected on the surface of a core layer which is colored with acoloring pigment.

[0092] The coloring pigment contained in the skin layer and the corelayer is suitably one or more kinds selected from a group of organicpigments such as phthalocyanine blue, cyanine green, indanthrene, azo,anthraquinone, perylene, perynone, quinacridone, isoindolinone,thioindigo, dioxazine; a group of inorganic pigments such as titaniumoxide, titanium yellow, red iron oxide, burned pigment, carbon black;and a group of dyes such as phthalocyanine, anthraquinone, perylene,perynone.

Granite Type of Additives

[0093] Many large opaque particles can be used to make the simulatedgranite. These particles can be colored or uncolored. Typical mineralparticles that can be used are calcined talc, magnetite, siderite,ilmenite, goethite, galena, graphite, anthracite and bituminous coal,chalcopyrite, pyrite, hematite, limonite; pyroxenes such as augite;amphiboles such as hornblende; biotite, sphalerite, anatase, corunbum,diamond, carborundum, anhydrite, chalk, diurite, rutile, sandstone,shale, slate, sparite, vermiculite, natural granite, peat and basalt.Other useful materials are chips of brick, charcoal, concrete, plaster,porcelain, sawdust, seashells, slag, wood and the like, various filledor pigmented chips of insoluble or crosslinked polymers such as ABSresins, cellulose esters, cellulose ethers, epoxy resins, polyethylene,ethylene copolymers, melamine resins, phenolic resins, polyacetals,polyacrylics, polydienes, polyesters, polyisobutylenes, polypropylenes,polystyrenes, urea/formaldehyde resins, polyureas, polyurethanes,polyvinyl chloride, polyvinylidene chloride, polyvinyl esters and thelike.

[0094] Useful large translucent and transparent particles are natural orsynthetic minerals or materials such as agate, alabaster, albite,calcite, chalcedony, chert, feldspar, flint quartz, glass, malachite,marble, mica, obsidian, opal, quartz, quartzite, rock gypsum, sand,silica, travertine, wollastonite and the like; and moderately filled orunfilled, pigmented or dyed, insoluble or crosslinked chips of polymersreferred to in the last paragraph.

[0095] The large opaque, translucent and/or transparent particles arepresent in the simulated granite at a concentration of about 0.1-50% byvolume, preferably about 1-35% by volume. The opaque particles are mostpreferably at a concentration of about 5-25% by volume while theconcentration of the translucent or transparent particles is mostpreferably about 5-30% by volume.

[0096] Additional additives can be included in the simulated granitearticle to give it decorative effects or to color the matrix background.These additives can be incorporated at a concentration up to about 10%by volume; however, when dyes or pigments are used to color the matrix,the color concentration cannot be so great as to hide the large opaque,translucent and transparent particles. The optical density of a 0.05inch thick wafer must be less than 3.0 and the surface must exhibit agranite-like pattern.

[0097] The surface patterns of a number of different natural graniteshave been defined by IMANCO® Quantimet 720 image analysis. Thesepatterns have about 0.1 to 40% area detectable at densitometric level820, about 0 to 30% additional area detectable at level 860, about 0.1to 25% additional area detectable at level 900, about 0 to 25%additional area detectable at level 950 and about 15 to 95% additionalarea detectable at a level greater than 950. It is preferred that thesimulated granite have essentially the same surface pattern.

[0098] In addition to dyes and pigments, other useful decorativeadditives are metallic fibers, dusts, flakes, chips or shavings such asaluminum, copper, bronze, brass, chromium, nickel, gold, iron, steel,platinum, silver, tin, titanium, tungsten, zinc and the like;non-metallic chips or flakes such as titanium nitride, nickel sulfide,cobalt sulfide, anhydrous chromic chloride and magnesium sulfide; andnatural or colored flocks or chopped fibers such as asbestos, rayon,cotton, nylon, flax, polyester, glass, hair, hemp, paper pulp,polyacrylonitrile, polyethylene, polypropylene, protein, rock wool, woodfiber, wool and the like.

[0099] The simulated granite is prepared by first preparing a castablecomposition. This composition can be made by preparing a mixture of thelarge opaque particles, the large transparent and/or translucentparticles and, if desired, any of the solid optional ingredients such asthe decorative particles. The matrix for the composition is prepared bymixing the polymerizable constituent, a viscosity control constituent,an initiating amount of an initiator system for the polymerizableconstituent, the small filler particles and any other optionalingredients such as a cross-linking or coloring agent. These twomixtures are mixed at a ratio which will give the desired visual effectin the final product and then this final mixture, called the castablecomposition is poured onto a surface which takes the form of the finalarticle, e.g. a flat surface for simulated granite sheets or a mold forsimulated granite shaped articles. The poured mixture is then curedautogenically. The matrix mixing can be conducted at a temperature inthe range of about 20° to 50° C. provided that the initiator system isnot added until ready to cast.

Colored Pigments

[0100] In general, the effect pigment is a metallic-effect pigment, ametal oxide-coated metal pigment, a platelike graphite pigment, aplatelike molybdenumdisulfide pigment, a pearlescent mica pigment, ametal oxide-coated mica pigment, an organic effect pigment, a layeredlight interference pigment, a polymeric holographic pigment or a liquidcrystal interference pigment. Preferably, the effect pigment is a metaleffect pigment selected from the group consisting of aluminum, gold,brass and copper metal effect pigments; especially aluminum metal effectpigments. Alternatively, preferred effect pigments are pearlescent micapigments or a large particle size, preferably platelet type, organiceffect pigment selected from the group consisting of copperphthalocyanine blue, copper phthalocyanine green, carbazole dioxazine,diketopyrrolopyrrole, iminoisoindoline, iminoisoindolinone, azo andquinacridone effect pigments.

[0101] Suitable colored pigments especially include organic pigmentsselected from the group consisting of azo, azomethine, methine,anthraquinone, phthalocyanine, perinone, perylene, diketopyrrolopyrrole,thioindigo, dioxazine iminoisoindoline, dioxazine, iminoisoindolinone,quinacridone, flavanthrone, indanthrone, anthrapyrimidine andquinophthalone pigments, or a mixture or solid solution thereof;especially a dioxazine, diketopyrrolopyrrole, quinacridone,phthalocyanine, indanthrone or iminoisoindolinone pigment, or a mixtureor solid solution thereof.

[0102] Colored organic pigments of particular interest include C.I.Pigment Red 202, C.I. Pigment Red 122, C.I. Pigment Red 179, C.I.Pigment Red 170, C.I. Pigment Red 144, C.I. Pigment Red 177, C.I.Pigment Red 254, C.I. Pigment Red 255, C.I. Pigment Red 264, C.I.Pigment Brown 23, C.I. Pigment Yellow 109, C.I. Pigment Yellow 110, C.I.Pigment Yellow 147, C.I. Pigment Orange 61, C.I. Pigment Orange 71, C.I.Pigment Orange 73, C.I. Pigment Orange 48, C.I. Pigment Orange 49, C.I.Pigment Blue 15, C.I. Pigment Blue 60, C.I. Pigment Violet 23, C.I.Pigment Violet 37, C.I. Pigment Violet 19, C.I. Pigment Green 7, C.I.Pigment Green 36, or a mixture or solid solution thereof.

[0103] Suitable colored pigments also include inorganic pigments;especially those selected from the group consisting of metal oxides,antimony yellow, lead chromate, lead chromate sulfate, lead molybdate,ultramarine blue, cobalt blue, manganese blue, chrome oxide green,hydrated chrome oxide green, cobalt green and metal sulfides, such ascerium or cadmium sulfide, cadmium sulfoselenides, zinc ferrite, bismuthvanadate and mixed metal oxides.

[0104] Most preferably, the colored pigment is a transparent organicpigment. Pigment compositions wherein the colored pigment is atransparent organic pigment having a particle size range of below 0.2μm, preferably below 0.1 μm, are particularly interesting. For example,inventive pigment compositions containing, as transparent organicpigment, the transparent quinacridones in their magenta and red colors,the transparent yellow pigments, like the isoindolinones or the yellowquinacridone/quinacridonequinone solid solutions, transparent copperphthalocyanine blue and halogenated copper phthalocyanine green, or thehighly-saturated transparent diketopyrrolopyrrole or dioxazine pigmentsare particularly interesting.

[0105] Adding a fluorescent dyestuff generates striking visual effectsfor the article. Suitable fluorescent dyestuffs include Permanent Pink R(Color Index Pigment Red 181, from Clariant Corporation), Hostasol Red5B (Color Index #73300, CAS # 522-75-8, from Clariant Corporation) andMacrolex Fluorescent Yellow 10GN (Color Index Solvent Yellow 160:1, fromBayer Corporation). Among these, Permanent Pink R is preferred.

[0106] Typically the pigment composition is prepared by blending thepigment with the filler by known dry or wet mixing techniques. Forexample, the components are wet mixed in the end step of a pigmentpreparatory process, or by blending the filler into an aqueous pigmentslurry, the slurry mixture is then filtered, dried and micropulverized.

[0107] In a preferred method, the pigment is dry blended with the fillerin any suitable device which yields a nearly homogenous mixture of thepigment and the filler. Such devices are, for example, containers likeflasks or drums which are submitted to rolling or shaking, or specificblending equipment like for example the TURBULA mixer from W. Bachofen,CH-4002 Basel, or the P-K TWIN-SHELL INTENSIFIER BLENDER fromPatterson-Kelley Division, East Stroudsburg, Pa. 18301.

[0108] The pigment compositions are generally used in the form of apowder which is incorporated into a high-molecular-weight organiccomposition, such as a coating composition, to be pigmented.

[0109] The pigment composition consists of or consists essentially ofthe filler and colored pigment, as well as customary additives forpigment compositions. Such customary additives include texture-improvingagents and/or antiflocculating agents.

[0110] The following patents relate to metallic type pigments. WO99/02594 which describes the use of rectangular aluminum flakes in Nyloncompositions., U.S. Pat. No. 5,091,010 and EP 0 426 446 relate to theaesthetics of molded articles containing flakes. These references do notaddress mechanical performance concerns which are addressed by thepresent invention.

[0111] Among the problems to be solved when utilizing polycarbonateresins and particles and pigments to produce special color effects arethose related to composition coloring and those related to producing avery bright, metallic reflective sparkle appearance in the moldedarticles while retaining impact strength and transparency. For mostvisual effects, it is desirable to have a completely transparent matrixin order to obtain the deepest color effect. The use of modifiers incombination various colorant additives may to be detrimental to physicalproperties such as notched Izod impact. Although various impactmodifiers are known in the prior art, the prior art is deficient inaddressing the problem of enhancing the impact properties ofpolycarbonate (alloys) having special effect colorants, whilemaintaining the transparency. The blend compositions as described inthis invention combine appealing aesthetics, chemical resistance, andhigh impact properties and will be useful in molded article applicationswhere this combination of properties is desirable.

Other Additives

[0112] Additionally, additives such as antioxidants, heat resistingagents, anti-weathering agents, mold release agents, lubricants,nucleating agents, plasticizers, flow-improving agents and anti-statics,quenchers, minerals such as talc, clay, mica, barite, wollastonite andother stabilizers including but not limited to UV stabilizers, such asbenzotriazole, supplemental reinforcing fillers such as flaked or milledglass, and the like, flame retardants, pigments or combinations thereofmay be added to the, compositions of the present invention. Theseadditives may be introduced in a mixing or molding process, provided theproperties of the composition are not damaged.

[0113] Suitable antistatic agents include, but are not limited to,phosphonium salts, polyalkylene glycols, sulfonium salts and alkyl andaryl ammonium salts.

[0114] Suitable mold release agents include, but are not limited to,pentaerythritol tetracarboxylate, glycerol monocarboxylates, glyceroltricarboxylates, polyolefins, alkyl waxes and amides.

[0115] In the thermoplastic compositions which contain a cycloaliphaticpolyester resin and a polycarbonate resin it is preferable to use astabilizer or quencher material. Catalyst quenchers are agents whichinhibit activity of any catalysts which may be present in the resins.Catalyst quenchers are described in detail in U.S. Pat. No. 5,441,997.It is desirable to select the correct quencher to avoid color formationand loss of clarity to the polyester polycarbonate blend.

[0116] A preferred class of stabilizers including quenchers are thosewhich provide a transparent and colorless product. Typically, suchstabilizers are used at a level of 0.001-10 weight percent andpreferably at a level off from 0.005-2 weight percent. The favoredstabilizers include an effective amount of an acidic phosphate salt; anacid, alkyl aryl or mixed phosphite having at least one acidic hydrogen;a Group IB or Group IIB metal phosphate salt; a phosphorus oxo acid, ametal acid pyrophosphate or a mixture thereof. The suitability of aparticular compound for use as a stabilizer and the determination of howmuch is to be used as a stabilizer may be readily determined bypreparing a mixture of the polyester resin component and thepolycarbonate and determining the effect on melt viscosity, gasgeneration or color stability or the formation of interpolymer. Theacidic phosphate salts include sodium dihydrogen phosphate, mono zincphosphate, potassium hydrogen phosphate, calcium dihydrogen phosphateand the like. The phosphites may be of the formula V:

[0117] where R1, R2 and R3 are independently selected from the groupconsisting of hydrogen, alkyl and aryl with the proviso that at leastone of R1, R2 and R3 is hydrogen.

[0118] The phosphate salts of a Group IB or Group IIB metal include zincphosphate and the like. The phosphorus oxo acids include phosphorousacid, phosphoric acid, polyphosphoric acid or hypophosphorous acid.

[0119] The polyacid pyrophosphates may be of the formula VI:

MzxHyPnO3n+1

[0120] wherein M is a metal, x is a number ranging from 1 to 12 and y isa number ranging 1 to 12, n is a number from 2 to 10, z is a number from1 to 5 and the sum of (xz)+y is equal to n+2. The preferred M is analkaline or alkaline earth metal.

[0121] The most preferred quenchers are oxo acids of phosphorus oracidic organo phosphorus compounds. Inorganic acidic phosphoruscompounds may also be used as quenchers, however they may result in hazeor loss of clarity. Most preferred quenchers are phosphoric acid,phosphorous acid or their partial esters.

[0122] The glass transition temperature of the preferred blend will befrom 60 to 150° C. with the range of 90-150° C. most preferred.

[0123] A flexural modulus (as measured by ASTM method D790) at roomtemperature of greater than or equal to 150,00 psi is preferred, with aflexural modulus of greater than or equal to 250,000 psi being morepreferred.

[0124] The yellowness index (YI) will be less than 10, preferably lessthan 5 as measured by ASTM method D1925.

[0125] Haze, as measured by ASTM method D1003, will be below 5% in thepreferred composition, however in some cases higher haze levels (5-60%)are preferred in cases where the highest heat resistance is needed.

[0126] Above described materials have also been tested in GE StructuredProducts applications like film and coextruded solid sheet materials. Infilm advantages like “cold” forming (the low Tg of the material enablesthe operator to use lower temperatures to thermoform the film), improvedtensile impact and chemical resistance were seen. These products willperfectly suit in applications like eg. transparent keypads for mobilephones, where customers require the possibility to form these films atlow temperatures (below 100° C.) and further require an improved punchductility and chemical resistance. Other typical applications of suchfilms are automotive trim, automotive interior parts, portabletelecommunications and appliance fronts. Another advantage in filmapplications is the possibility to add Visual effects pigments (such ascoated Al and glass flakes), which are normally negatively affecting themechanical properties of Polycarbonate, to this PC/PCCD/ABS blend toenhance required Impact properties. These films can be used in directfilm applications but also in processes like IMD (In Mould Decoration).

EXAMPLES

[0127] The following examples serve to illustrate the invention but arenot intended to limit the scope of the invention. Blends were preparedby tumbling all ingredients together for 1-5 min at room temperaturefollowed by extrusion at 250-300° C. on a co-rotating 30 mm vacuumvented twin screw extruder. Blends were run at 300 rpm. The output wascooled as a strand in a water bath and pelletized.

[0128] The resultant materials were dried at 100-120° C. for 3-6 h andinjection molded in discs or sections of discs (fans) for evaluation ofoptical properties.

[0129] Blends of PCCD with BPA-PC and various impact modifiers wereprepared and various stabilizers were added to give good color and meltstability. The samples were compounded on a twin screw extruder andinjection-molded at standard conditions.

Example 1

[0130] MVR PC PCCD (cc/10′) 105 4000 Impact PC/PCCD Transmission (300°C. D/B Batch # grade % poise % stabilizers % Modifier % ratio 2 mm % 1.2kg) ° C. 1 99.8 0.2 91.4 5.1 −10 2 69.6 30 0.4 70/30 90.4 16.8 0 3 28.466.2 0.4  5% MBS 30/70 89.5 31.6 −20 4 25.4 59.2 0.4 15% MBS 30/70 88.514.3 −32 5 30.6 54 0.4 15% clear 36/64 89.6 22.2 −6 ABS 6 47.3 47.3 0.410% ABS 415 50/50 89.8 7.4 −22 7 46.6 38.1 0.4 15% ABS 336 45/50 88.16.7 −33 8 67.2 22.4 0.4 10% ABS 336 25/75 77.1 4.8 −32

[0131] From the data batch 1 -7 it is clear that adding PCCD to PC givesa significant improvement in flow. Adding impact modifiers not onlygives an improvement in flow, but also improves low temperatureductility, while obtaining high transparencies in the same range as PC.

[0132] In some cases lower amounts of PCCD are desired, than the onesmentioned in batch 2-7. This can be from a cost perspective or that forsome applications more heat is required. Although this will result inlower transmission values (the 100 % match of RI is no longer present inthe blend), in many cases these values are still high enough to allowfor adding special/visual effects like glass or metal flakes and in somecases some translucency is even desired. A typical example is given inthe table for batch 8.

Example 2

[0133] These property enhancements are further illustrated in the nexttable, in which some typical comparisons are made between PC formulatedwith special effects and blends of PC/PCCD and impact modifier,formulated with the same type of special effects. MVR PC PCCD (cc/10′)105 2000 Impact (265° C. D/B batch # grade % poise % stabilizers %Modifier % Special Effect 5 kg) ° C. 9 98.3 0.5 1.2% glass/silver10.1 >25 flakes 10 41.7 41.7 0.4 15% ABS 1.2% glass/silver 12.8 −22 415flakes 11 99.3 0.5 0.2% variochr. red 10.4 >25 (AngularMetameric) 1241.7 41.7 0.4 15% ABS 0.2% variochr. red 12.8 −18 415 (AngularMetameric)

[0134] It is obvious from the data that typical effects like glass andmetal flakes turn PC into very brittle blends. However with the correctPCCD and impact modifier loading, the visual effect was very similar tothe PC sample, but the blend was still ductile at lower than 0° C. andeven had an improved flow. This remarkable achievement of highlyductile, transparent materials with special effects like AngularMetamerism, Diamond, Diffusion and Pearl effects is not restricted tothe ones mentioned in the examples.

Example 3

[0135] Film material with a thickness of 220 microns was produced from a45/45/10% ratio PC/PCCD/ABS blend and tested with 100% PC film as rencematerial. Following results were obtained: Film sample 2 Film sample 3Film sample 1 45/45/10% 40/60% Test name: 100% PC PC/PCCD/ABS PC/PCCDTensile Impact Kj/m2 961 1129 1147 Elongation to br. % 75.2 98.3 87.5After stress cracking 102.8 126.4 154.6 “sweat” test: Tensile Strain atmax % Taber Abrasion ASTM 27 24 19 D1044 25 Rotations Haze %

[0136] From this example it is apparent that impact properties of filmmaterial made from PC/PCCD mixtures is improved significantly comparedto PC alone, either with or without adding impact modifiers. Also thechemical resistance towards artificial sweat has improved.

Example 4

[0137] The polyester PCCD (with low RI[RI of PCCD˜1.525) that is fullymiscible with PC can be used to lower the RI of the PC phase (phase 1)to the RI of a clear ABS (that has RI of SAN and Rubber phases alreadymatched). This results in transparent PC/SAN/rubber blend. Mixtures ofPC/PCCD resulted in linear RI going from 1.525 to 1.577 when using 100%PCCD to 100% PC respectively. The Clear ABS that was utilized in thisexample had a RI of 1.548. In order to match this a PC/PCCD ratio of 54to 31 was prepared and mixed with 15 wt. % of clear ABS. The results ofsamples from this blend were as follows: Transmission (%, 3.2 mm) 85Haze (ASTM9125) 15

[0138] The refractive index of pure polycarbonate (PC) is 1.586 whilethat of PCCD is 1.516. In a mixture of polycarbonate and poly(1,4-cyclohexanedimethanol-1,4-cyclohexanedicarboxylate the refractiveindex of the mixture, y, varies as the function −0.0007 (weight percentpoly (1,4-cyclohexanedimethanol-1,4-cyclohexanedicarboxylate)+1.586 witha regression R squared coefficient of 0.998. Thus the refractive indexof the mixture of the two components may be controlled between the upperand lower limits of their respective indices of refraction.

What is claimed is:
 1. A composition comprising a uniform blend of: a) aresin blend of a polycarbonate resin and a cycloaliphatic polyesterresin, said cycloaliphatic polyester resin comprising the reactionproduct of an aliphatic C₂-C₁₂ diol or chemical equivalent and a C₆-C₁₂aliphatic diacid or chemical equivalent, said cycloaliphatic polyesterresin containing at least about 80% by weight of a cycloaliphaticdicarboxylic acid, or chemical equivalent, and/or of a cycloaliphaticdiol or chemical equivalent; and b) an impact modifying amorphous resinhaving a refractive index from about 1.51 to about 1.58; wherein themiscible blend comprises the polycarbonate and the cycloaliphaticpolyester resin in amounts such that the index of refraction of theblend matches the index of refraction of said impact modifier to producea transparent or translucent composition.
 2. The composition accordingto claim 1, wherein the cycloaliphatic polyester resin comprises thereaction product of a C₆-C₁₂ cycloaliphatic diol or chemical equivalentand a C₆-C₁₂ cycloaliphatic diacid or chemical equivalent.
 3. Thecomposition according to claim 2, wherein the ratio of polycarbonateresin to cycloaliphatic polyester resin in the blend is from 95/5 to20/80, and wherein the composition comprises from 1 to 30% by weight ofthe impact modifying amorphous resin.
 4. The composition according toclaim 1, wherein the impact modifying amorphous resin is selected fromthe group consisting of graft or core-shell acrylic rubbers, dienerubber polymers and silicone rubber polymers.
 5. The compositionaccording to claim 4, wherein the impact modifying amorphous resincomprises a MBS core-shell polymer.
 6. The composition according toclaim 5 in which the impact modifying amorphous resin comprises an ABSrubber.
 7. The composition according to claim 1 where the blend has %transmittance of greater than or equal to 75%.
 8. The compositionaccording to claim 1 where the blend has a glass transition temperatureof from 60 to 150° C.
 9. The composition according to claim 1 with theaddition of about 0.0001 to about 7 percent by weight of metal ormineral flakes for imparting a desired visual effect, said impactmodifier enhancing the impact strength of molded composition as comparedto a molding composition absent said impact modifier.
 10. Thecomposition according to claim 9 wherein said flakes are aluminum. 11.The composition according to claim 9 wherein the flakes comprise fromabout 0.05 to about 5.0 weight percent of the resin composition.
 12. Thecomposition according to claim 9 wherein said flakes are metal and rangein size from 17.5 microns to 650 microns.
 13. The composition accordingto claim 9 wherein the flakes are metal and are selected from the groupconsisting of metals of Group I-B, III-A, IV, VI-B and VIII of theperiodic table and physical mixtures and alloys of these metals.
 14. Thecomposition according to claim 9 wherein the flakes are mica.
 15. Thecomposition according to claim 9 wherein the flakes are metal andselected from the group consisting of aluminum, bronze, brass, chromium,copper, gold, iron, molybdenum, nickel, tin, titanium and zinc, alloysof these metals and physical mixtures thereof.
 16. The compositionaccording to claim 9 further comprising a background colorant having adifferent coloration than said flakes.
 17. The composition according toclaim 16 wherein said colorant is selected from the group consisting ofcarbon black, phthalocyanine blues, phthalocyanine greens, anthraquinonedyes, scarlet 3b Lake, azo compounds, acid azo pigments, quinacridones,chromophthalocyanine pyrrols, halogenated phthalocyanines, quinolines,heterocyclic dyes, perinone dyes, anthracenedione dyes, thioxanthenedyes, parazolone dyes and polymethine pigments.
 18. The compositionaccording to claim 1 where the blend further contains an effectiveamount of a stabilizer to prevent color formation.
 19. The compositionaccording to claim 18 wherein the stabilizer is chosen from the groupconsisting of: phosphorus oxo acids, acid organo phosphates, acid organophosphites, acid phosphate metal salts, acidic phosphite metal salts ormixture thereof giving an article with greater than or equal to about70% transmittance.
 20. The composition according to claim 1 wherein thecycloaliphatic polyester is comprised of cycloaliphatic diacid andcycloaliphatic diol units.
 21. The composition according to claim 20where the polyester is polycyclohexane dimethanol cyclohexanedicarboxylate (PCCD).
 22. The composition according to where thepolycarbonate is BPA-PC and the cycloaliphatic polyester is PCCD. 23.The composition according to claim 22 where the ratio of cycloaliphaticpolyester to polycarbonate in the blend is 5/95 to 80/20.
 24. Thecomposition according to claim 23 wherein said blend further contains aneffective amount of a stabilizer to prevent color formation.
 25. Thecomposition according to claim 24 wherein said stabilizer is chosen fromthe group consisting of: phosphorus oxo acids, acid organo phosphates,acid organo phosphites, acid phosphate metal salts, acidic phosphitemetal salts or mixture thereof for making a molded article with greaterthan or equal to about 75% transmittance.
 26. The composition accordingto claim 25 wherein said cycloaliphatic polyester comprisescycloaliphatic diacid and cycloaliphatic diol units.
 27. The compositionaccording to claim 1, further comprising an effect-producing amount ofan effect pigment, an effective coloring amount of a colored pigment,and an effect-enhancing amount of a small particle size filler having aporous surface.
 28. The composition according to claim 1, furthercomprising an effect-producing amount of a metallic, pearlescent mica orgraphite effect pigment, a transparent organic pigment as the coloredpigment and
 29. A process for molding a transparent article comprisingthe steps of (a) selecting a transparent impact modifier having apredetermined index of refraction, (b) forming a resin blend comprisinga cycloaliphatic polyester and a polycarbonate, wherein thecycloaliphatic polyester and the polycarbonate are mixed in the resinblend in proportions such that the resin blend has an index ofrefraction that substantially matches the predetermined index ofrefraction, (c) forming a molding composition comprising the selectedimpact modifier and the resin blend; and (d) molding an article from themolding composition.
 30. The process of claim 27, wherein said moldingis carried out above the glass transition temperature of said resinblend, said resin blend having a glass transition temperature of fromabout 60 to 150° C.
 31. The process of claim 28 wherein said molding iscarried out by injection molding.
 32. A process for forming a moldingcomposition for preparing transparent articles comprising the steps of(a) selecting a transparent impact modifier having a predetermined indexof refraction, (b) forming a resin blend comprising a cycloaliphaticpolyester and a polycarbonate in proportions such that the resin blendhas an index of refraction that substantially matches the predeterminedindex of refraction, and (c) mixing the impact modifier and the resinblend to form a molding composition.
 33. A transparent extrusion sheetproduct having a thickness of from 10 um to 12 mm formed from acomposition according claim 1.